Irving Azoff and Sharon Osbourne are firing back at a recent statement released by AEG Presents’ Jay Marciano in the ongoing Venue Wars between AEG and MSG & Live Nation, with the Azoff MSG Entertainment chairman calling a claim that AEG is an artist-friendly company “a pack of lies.”

Sharon Osbourne was equally irked, telling Marciano “Your note is contradictory to the facts and I find the way you’re conducting yourself and your company to be no more than childish playground tactics.”

She went on to ask why AEG Presents told her “Ozzy cannot play at the 02 in London unless we legally agree to play at Staples Center in Los Angeles? This is a staggering attempt to blackmail Ozzy into playing your venue in Los Angeles. It is also a complete abuse of bargaining power and not conducive to a free market. If you do not confirm the date for OZZY at the O2 in London then I will be forced to take legal action against AEG Live without delay.”

Both letters are part of a fast-moving spat that began Wednesday after Osbourne publicly called out AEG for attempting to force Ozzy to play the Staples Center in Los Angeles in return for a February 2019 date at the O2 Arena in London — Ozzy ultimately opted to play the Hollywood Bowl on Oct. 11 as part of his No More Tours 2 run.

After publishing the first of two letters calling out calling out AEG for the block booking policy, Marciano responded to Sharon in a letter stating his policy was a response to similar demands by Azoff MSG Entertainment requiring artists to play the Forum, concluding his note “PS – The other guys started this first!”

Today, Azoff came forward with his own retort to the public conversation.

Azoff wrote “Dearest Jay – This is a pack of lies. I’ve put artists first my entire career, name one time you’ve put an artist above your own self-interest. Why do they continue to do business with you? We do not block book Madison Square Garden and The Forum, it is well-established. You guys continue to use lies to validate your anti-artist, anti-industry behavior. Love, Irving. PS – Sharon, you rock. You’re welcome at The Forum any time.”

The public exchanges began after Ozzy Osbourne announced his farewell solo tour on Wednesday. For his final world tour, the Prince of Darkness placed a Feb. 11, 2019 hold for the O2 Arena in London and received a “Staples Center Commitment” letter from AEG that states that if Ozzy lands the O2 Arena dates, “and plays an indoor arena anywhere within 25 miles of the City of Los Angeles as part of the same tour cycle as the aforementioned The O2 Shows and that show/those shows is/are promoted by a Live Nation Entertainment, Inc. group company, then you shall ensure at least one of those Ozzy Osbourne shows in Los Angeles shall be held at the Staples Center.”

Marciano has previously said that AEG Presents adopted the block booking policy between Staples Center and The O2 Arena after Azoff said in April that “the premium MSG nights are going to loyal friends of the company. Playing the Forum — the obviously better music venue in Los Angeles — makes you a friend of the company.” Since then, Azoff has changed course and repeatedly said there is no block booking policy between Madison Square Garden and The Forum.

Months later, Marciano told Amplify founder Dave Brooks during a keynote interview at the Billboard Touring Conference that AEG will continue their block-booking of Staples Center and The O2 Arena until they reach “a comfort level” and “feel like it is believable [that MSG is not block booking.], adding “I also want to establish that if it happens again, we’re perfectly prepared to go back to the way it is right now.”

The bruhaha officially began Wednesday when Sharon Osbourne called out the “Staples Center Commitment” letter, writing “Mr. Marciano, I am returning the enclosed Staples Center Commitment Agreement to you, unsigned. Shame on AEG for bringing artists into a power struggle you’re having with your competitor, Live Nation. I can assure you that Live Nation would never strong-arm an artist into playing a venue they’re not comfortable performing in.”

She continued “Without the artists there would be no AEG, no Live Nation, no promoters, agents or managers. The artists should always come first. Never forget that! There’s enough for everyone without you trying to monopolize the world of entertainment.”

Marciano responded later that evening, writing “Dear Sharon, Thank you for your note. Please understand this dispute is between The Forum and Staples Center and we couldn’t agree with you more — it should always be the artist’s choice. We long for the days when artists and fans came first.” His note concludes with “PS – The other guys started this first!”

Live Nation U.K. chairman Denis Desmond filed a complaint last year with the Competition and Market Authority (CMA) in England about AEG’s arrangement. In December, the CMA announced it would not be investigating AEG’s policy, essentially giving the green light to the venue-tying.